The present invention generally relates to water heaters and, in a representatively illustrated embodiment thereof, more particularly provides a specially designed endothermic heat pump water heater.
Water heaters incorporating, as a heat source, a heat pump circuit in addition to a fuel-fired or electric resistance type water heating system are known in the water heating art. While the heat pump circuit, due to its high thermal efficiency, has typically been viewed as a useful addition to conventional water heating apparatus such as electrical resistance heating elements, it has been seen as desirable design goal to improve in water heating applications various characteristics of conventionally constructed heat pump circuits. Such desired improvements include increasing the reliability and thermal efficiency of such heat pump circuits, reducing their noise generation, and reducing undesirable heat transfer from the water heater tank to cooled air flow created by operation of the heat pump circuit. It is to this design goal that the present invention is primarily directed.